Device for scoring glass sheets

ABSTRACT

A device for scoring glass sheets by following the profile of an outer periphery of a template for the purpose of breaking the glass sheets. The device comprises an integrally and stepwiseformed shaft means including a center shaft, an intermediate offset shaft, and a third offset shaft forming the longitudinally lowest part and radially outermost part of the shaft means, and a cutter means mounted at the lower end of the third shaft. The intermediate shaft is urged in a direction to keep the center shaft in operative engagement with the template. A follower roller means can be mounted on the center shaft to facilitate the engagement with the template.

United States Patent DEVICE FOR SCORING GLASS SHEETS 3 Claims, 6 Drawing Figs.

us. Cl 83/12, 33/27, 83/565 Int. Cl. B26d 3/08 Field of Search 33/27 K;

[56] References Cited UNITED STATES PATENTS 552,293 12/1895 Kuhn 33/27 2,156,847 5/1939 Gregory 33/27 Primary Examiner-James M. Meister Attorney-Waters, Roditi, Schwartz, & Nissen ABSTRACT: A device for scoring glass sheets by following the profile of an outer periphery of a template for the purpose of breaking the glass sheets. The device comprises an integrally and stepwise-formed shaft means including a center shaft, an intermediate offset shaft, and a third offset shaft forming the longitudinally lowest part andradially outermost part of the shaft means, and a cutter means mounted at the lower end of the third shaft. The intermediate shaft is urged in a direction to keep the center shaft in operative engagement with the template. A follower roller means can be mounted on the center shaft to facilitate the engagement with the template.

PATENTEDJAM 91971 3555; 94

' sum 1 or 2 -I PRIORART' j v vature.

face corresponding to that of the template. I Other objects and features of the present invention will'be fully understoodfrom thefollowing description taken in coni junction with'the accompanying drawings, in which:

DEVICE roascoamcclsAss snaars" i scoring glass-sheets for breaking the glass sheets by profiling the outer periphery of a templatewhich makes it possible to makecurved scores effectively with a very small radius of cur- According tothe presentinventioninorderfto attain the aforesaidpbject, there -.-isrprovided a device forscoring glass sheets by profiling the outer peripheryof a template comprising an integrally and. stepwise-formed shaft means including a centershaft, an intermediate offset'shaft; and a .thirdoffset shaft, said third shaft .being longitudinallyv and radially more spaced apartrfrom said. center\shaft't'han said intermediate shaft and the axisthereof being in parallelrelation in the same plane with theaxes of i the intermediate and center-shafts, and a.wheelcutterrotatablysupported at the tip of said .third offset shaft for scoring glass= sheets, said intermediate shaft being urged in a direction to follow the accurate profileof the outer periphery. of the. template. .The device forscoring glass sheets. further comprises a followerroller means rotatably mounted.

at the distal end of the center-shaft so as to slidably engage the outer periphery of the template. in another embodimentof the presentinvention, the. template has a tapered outer surface and thefollower roller also has at least one tapered outer sur- FIG. [is a diagrammaticillustration'of the operative conception of a known device for scoring glass sheet;

1. FIG. la is a schematic side view of the known scoring device embodying the conception ofFIG. 1-,

FIG. 2 is a diagrammatic?illustration of the operative conception of scoring .motion in a device accordingto the present" invention;

FIG-.3 isaschematic view ofra scoring device, illustrating 2 various shaft positionsof the scoring device relative to a template;

FIG. 4 is a schematic and partial sectional view of a scoring device aecordingto' the .presentinvention, showing a template and afollower roller thereofrand a fragmental plan view'ot the axes thereof; and

FIG. 5 is anotherischematic sectional view of the scoring device showing the follower roller'in the state:as engaging a guide plate mountedon the template.

Similarparts and=members are designated by the same numetals and symbols throughout the drawings.

In a device for scoringglass sheetsby profilingthe outer periphery of a template'orguideplatewhile urging a follower rolleragainst the template by a force F,'if the' device has a scoringwheel cutter rotatably mountedat the tip=of a shaft concentrically extending along the axis ofthe follower roller, the cuttercan make scores; by profiling the configuration'of the template as long asthe outer periphery'ofthe template is a smooth curve with a radiusof curvaturelargerthan a certain limit. However, if the radius of curvature of the template periphery becomessmallerthan the certain limit, especially at a right-angled corner, the cutter moves along an arcuate locus with the radius of-thefollower roller and the configuration of the outer peripheryof the template cannot reproduce accu rately in the scores formedon the glass sheets.

In orderto obviate such a difficulty, it has been proposed to use an:eccentric'ortoffsetshaft, as shown in'FIG. 1a. In the FIG., a follower-roller! has a concentric shaft 2, and an ecv centric shaft 3 is integrally connected to the concentric shaft 2 with an offset equivalent to the radius of the followerroller 1. In other words, the axis of the eccentricshaft 3 intersects the outer periphery of theafollower'roller l. The eccentric shaft 3 is urged towarda template 4 by a force F. A wheel cutter 5 is 3, as-shown in FIG. 1a. A glass sheet 20 is scored by the rotation of the wheel cutter 5 while moving the follower roller 1 along the outer periphery of the template 4.-

Referring to FIG. 1, illustrating the operative conception of the scoring device of FIG. la, the wheel cutter 5 at the position A, which is offset from the axis 0 of the follower roller and rolling along the outerperiphery of the template 4, is urged by the force F extended normally to the periphery of the template. At the same time, the axis of the follower roller is moved by a driving force along the periphery of the template .at a velocity v. The follower roller is also rotated by the force F, but since the force F is'exerted at a right angle with respect to the-moving direction of the follower roller, the side faces of .the cutter turn perpendicularly to the urging force F and the .larly'on the template. By repeating such a movement, the follower roller rolls along the template outer periphery and causes'the wheel'cutter to move on the'corresponding locus for making the desired scores on the glass sheet. Moreexactly, the'cutter receives not only'thenormal force F, but also the driving force v transmittedfrom the follower roller. As a result, the composite force of the two forces F and v has a small deviation from the normal line to the template outer periphery, or the cutter is urged to the template periphery in a slightlydeviated angular relation. As long as the template outer periphery is smoeth with a large radius of curvature, the aforesaid small deviation of the composite force does not introduce anyserious error in the movement of the cutter, and scores can be formed by exactly reproducing the configuration of the template periphery. l-Iowever, if the radius of curvature of the outer periphery of the template becomes smaller than a certain limit, the cutter begins to fluctuate angularly about axis 0 of the follower roller because of the two forces F and v. Consequently, at such an acute corner with a small radius of curvature, since the offset shaft is not perpendicu-' larly urged with respect to the template, the faces of the wheel cutter, in the transition position, cannot turn exactly to a right angle with respect to a perpendicular line from the axis of the follower roller to the relatedportion of the outer periphery of the template. Accordingly, at such an acute corner, the scoring on the glass sheet is deviated from the template configuration.

The inventor made studies on the solution of such difficulties, and as a result, he has discovered the following fact. Suppose that a cutter roller received a driving force which acts on the axis 0 of a follower rollerto move it parallel with the tem- The last mentioned force acts only in a direction to urge the wheel cutter to thetemplate periphery, but not in a direction to rotate or fluctuate thewheel cutter about the follower roller axis 0. Thus, the cuttercan score the glass sheet while exactly following the template outer periphery.

The conception of such a cutter movement will now be descfibed in further detail, referring to FIG. 2. An intermediate offset shaft P is integrally formed with the shaft of the follower roller, and another sha'ft carrying thewheel cutter is concentrically mounted at thelower end of the eccentric shaft integrally formed with'the intermediate offset shaft. In a plan view, the axial projection point of the intermediate shaft is located on a line connecting the axial projection point of the follower roller with the projection point of said other or third shaft carrying the cutter and the three axes are in parallel relation; As in the case of FIG. 1, assume that the wheel cutter is moved from a position B to another position 8,. As the axis of the follower roller moves from a position 0 to another position 0", the intennediate shaft moves to a position P. If the intermediate shaft P is urged by an urging force toward the template in a direction perpendicular to the template periphery, the effect of such urging force is not changed by the movement of the intermediate shaft P to the position P. The wheel cutter thus moves from the position B to 8 so as to follow the shape of the template periphery, as in the case of Flg. 1. With the arrangement of FIG. 2, the driving force v acting on the follower roller simply causes the follower roller to slide along the template outer periphery. The urging force F acting on the intermediate shaft P in a direction perpendicular to the template periphery simply urges the cutter to the template, and does not cause the wheel cutter to rotate about the axis of the follower roller by acting at a point between an acting point and the cutter. Consequently, the wheel cutter moves while exactly following the configuration of the template outer periphery without deviating therefrom, so that the scoring can be made by exactly reproducing the template configuration.

The present invention is based on the aforesaid discovery. The device of the invention will now be described in further detail referring to FIGS. 3 to 5. An integral step-shaped shaft means 11 includes a center and upper shaft 12, an intermediate offset shaft 13, and another offset or third shaft 14. As shown in a plan view seen in the direction of the arrow C of FIG. 4, the projection points of the axes l, m, and n of the shafts 12, 13 and 14 are on a radius extending from the axis I, said axis n being spaced farther away from the axis 1, as shown at n, m', and l in the plan view shown in dotted outline. The center shaft 12 has an assembly of a pair of truncated conical members 15 and 16 concentrically mounted thereon in tan dem. Suitable bearings extend through central holes of the truncated conical members so as to rotatably support them. The inten'nediate offset shaft 13 is rotatably carried by a pushing means 1'! through a suitable bearing means. A wheel cutter 18 is rotatably mounted at the lower end of the shaft 14 by a suitable known means, and the cutter can be rotated about the mounting pin of the shaft 14. The outer peripheral edge of a template 19 is slanted at the same slope as that of the upwardly convergent truncated conical members and 16. The numeral 20 represents a glass sheet to be scored by the wheel cutter 18.

Referring to FIG. 4, the scoring device having the cutter 18 mounted at the lower end of the shaft means 11 is moved on the glass sheet 20, while exerting a force F on the shaft means by the pushing means 17 at a right angle with respect to the outer periphery of the template, and then the truncated conical member 15 rolls along the periphery of the template. As a result, the wheel cutter scores the surface of the sheet 20, while the member 15 is profiling the outer periphery of the template. In this case, due to the urging force F applied to the intermediate shaft 13 by the pushing means, the wheel cutter 18 moves directly underneath a predetermined level (in the illustrated embodiment, the lower end) of the slanted edge of the template periphery, so as to score the glass sheet while exactly reproducing the configuration of the template. Even when the shaft means encounters an acute corner of the template, e.g. a right-angled corner, the urging force F effectively urges the shaft means to the template in a direction perpendicular to the template outer periphery, so that there is not produced any force tending to rotate the shaft means 11 about the axis I of the center shaft 12. Thus, the scoring can be made exactly profiling the configuration of the template, even at right-angled corner portions, as shown at the upper right comer of FIG. 3.

FIG. 5 illustrates the use ofa guide plate, which is useful for making nonclosed scoring, or for moving the scoring device along the template without actually effecting the scoring the the sheet glass. A guide plate 22 is mounted on the template 19 with spacers 21 inserted therebetween. The operative edge of the guide plate 22 is slanted or tapered with the same gradient with that of the peripheral edge of the template 19. As the intermediate shaft 13 is urged towards the template 19 at a right angle with respect to the outer periphery, the upwardly convergent surface of the truncated conical member 16 engages the slanted surface of the guide plate 22, so that the cutter comes directly underneath a predetermined point of the truncated conical member 16, or directly beneath the lower end of the slanted surface of the guide plate. Thus, the wheel cutter moves away from the corresponding position of the template periphery. Consequently, as the cutter traces along a line outwardly offset from the corresponding peripheral line of the template, the glass sheet is not scored as long as the truncated conical member 16 engages the guide plate 22.

As described in the foregoing in the case of scoring glass sheet by profiling the outer periphery of a template, the device according to the invention can precisely score the surface of the glass sheet even at an acute corner of the template with a very small radius of curvature. If the peripheral edges of the template and the guide plate mounted on the template are slanted or tapered, and if the cooperating edge of the follower roller is similarly tapered, a glass sheet can be scored following any desired peripheral edge portion of the template by securing the template at a suitable height. Furthermore, instead of the truncated conical follower roller members 15 and 16, it is possible to bring the center shaft 12 in direct contact with the template, so as to score the glass sheet by moving the shaft 12 along the template while urging the intermediate shaft toward the template by suitable pushing means. is, of course, possible not to slant or taper the peripheral edge of the template, so that the glass sheet can be scored by causing a cylindrical follower roller to engage the template.

Although the present invention has been described with reference to particular embodiments, it is understood that the present disclosure has been made by way of example and that numerous changes and modifications in the details of construction and the combination and arrangement of parts may be resorted to without departing from the scope of the invention as hereinafter claimed.

Iclaim:

1. A device for scoring glass sheets by profiling the outer periphery of a template, comprising an integrally and stepwise-formed shaft means including a center shaft, an intermediate offset shaft and a third offset shaft, said third offset shaft being longitudinally and radially spaced at a greater distance from said center shaft than said intermediate offset shaft and the axes of said shafts being parallel and in the same plane, and a wheel cutter rotatably supported at the tip of said third offset shaft for scoring the glass sheets, said intermediate shaft being urged in a direction to follow the profile of the outer periphery of the template.

2. A device for scoring glass sheets as defined in claim 1, further comprising a follower roller means rotatably mounted at the distal end of the center shaft so as to slidably engage the outer periphery of the template.

3. A device for scoring glass sheets as defined in claim 2, wherein said template has a tapered outer surface and said follower roller also has at least one tapered outer surface corresponding to that of the template. 

1. A device for scoring glass sheets by profiling the outer periphery of a template, comprising an integrally and stepwiseformed shaft means including a center shaft, an intermediate offset shaft and a third offset shaft, said third offset shaft being longitudinally and radially spaced at a greater distance from said center shaft than said intermediate offset shaft and the axes of said shafts being parallel and in the same plane, and a wheel cutter rotatably supported at the tip of said third offset shaft for scoring the glass sheets, said intermediate shaft being urged in a direction to follow the profile of the outer periphery of the template.
 2. A device for scoring glass sheets as defined in claim 1, further comprising a follower roller means rotatably mounted at the distal end of the center shaft so as to slidably engage the outer periphery of the template.
 3. A device for scoring glass sheets as defined in claim 2, wherein said template has a tapered outer surface and said follower roller also has at least one tapered outer surface corresponding to that of the template. 